Interest in solar power is increasing with large scale projects planned in Portugal and the Philippines. Large energy giants like BP and Royal Dutch Shell are involved in producing equipment. The agricultural valleys of California are considered favorable for solar power. Home conversions to solar power will probably require subsidies to offset initial costs but will lead to low monthly bills. Improvements in semiconductors will aid solar development. Solar panels on trains in Italy and Japan provide for air conditioning, illumination and safety systems. Solar cars and backpacks have been developed. 